Impact of Physical Objects on Scaring of Geese – with an Agroecological Approach Towards the Issue of Geese As a Pest in Agriculture
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Impact of Physical Objects on Scaring of Geese – With an agroecological approach towards the issue of geese as a pest in agriculture Påverkan av fysiska objekt på skrämsel av gäss - Med ett agroekologiskt grepp på gäss som skadegörare i lantbruket Elias Kvarnbäck Independent project • 30 credits Swedish University of Agricultural Sciences, SLU Faculty of Landsacape Architecture, Horticulture and Crop Production Sience Agroecology – Master’s programme Alnarp, 2021 Impact of Physical Object on Scaring of geese – With an agroecological approach towards the issue of geese as a pest in agriculture Påverkan av fysiska objekt på skrämsel av gäss – Med ett agroekologiskt grepp på gäss som skadegörare i lantbruket Elias Kvarnbäck Supervisor: Johan Månsson, SLU, Department of Ecology, Wildlife Ecology Unit Assistant supervisor: Johan Elmberg, Kristianstad University, Department of Environmental Science and Bioscience Examiner: Matias Jonsson, Swedish University of Agricultural Sciences, SLU, Department of Ecology Credits: 30 credits Level: Advanced level, A2E Course title: Independent project in Agricultural Science, A2E – Agroecology – Master’s programme Course code: EX0848 Programme/education: Agroecology – Master’s programme Course coordinating dept: Department of Biosystems and Technology Place of publication: Alnarp Year of publication: 2021 Keywords: Geese, barnacle goose, greylag goose, large grazing birds, agroecological practices, flight initiation distance Swedish University of Agricultural Sciences Faculty of Landscape Architecture, Horticulture and Crop Production Science (LTV) Department of Biosystems and Technology Publishing and archiving Approved students’ theses at SLU are published electronically. 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Abstract The interactions and conflicts between geese and agricultural interests have risen in the last decades in Sweden. A range of measures are used by humans to disturb and scare geese with the goal to counteract crop damage. The hypothesis of this master thesis is that proximity to physical objects taller than 70 cm above the ground, e.g., woody perennials, houses or naturally occurring topographical features, makes greylag and barnacle geese easier to scare off crops. The incentive to inquire the effect of physical objects on scaring is that landscape and field features such as hedges, agroforestry and buffer strips are often suggested as agroecological practices. Presence of such element is relevant since geese tend to prefer to forage on fields with good visibility range. The data collected could however not prove that geese are more easily scared/disturbed as they are closer situated to physical objects. Among mixed flocks and greylag goose flocks, proximity to physical objects even made them harder to scare away from agricultural fields. Keywords: Geese, barnacle goose, greylag goose, large grazing birds, agroecological practices, flight initiation distance Preface The broad scope of agroecology presents many opportunities for master thesis topics. Especially if one embraces the food system approach and not just the agroecosystem. I struggled for a while to choose my topic, but a basic yet very powerful sentence that made me finalize my choice, was the following (Smith & Smith 2015 p. 87): How adaptations enable an organism to function in the prevailing environment – and conversely how those same adaptations limit its ability to function in other environment – is the key to understanding the distribution and abundance, the ultimate objective of the science of ecology. During my time as a master student, I’ve sometimes felt that the approach in classical ecology differs a lot from the agroecological approach, where the latter is much more applied and value driven. The interactions between geese on agricultural land and humans, should therefore be seen from an applied perspective, if it is to be considered agroecology. To write a master thesis, has been quite a different process and feeling than taking other university courses. Without my helpful and cheerful supervisors Johan Månsson and Johan Elmberg, I’d probably have felt lost and bored. The skills, that I’ve trained and come to value the most while writing my master thesis, are probably statistics in R as well as practical field work. Critical thinking and writing came naturally to me after 1.5 years of courses in agroecology. Table of contents 1. Introduction ............................................................................................................. 10 Hypothesis and aim ..................................................................................... 11 Study design ................................................................................................ 12 2. Background ............................................................................................................. 13 Geese .......................................................................................................... 13 2.1.1. Taxonomy and species identification .................................................. 13 2.1.2. Physiology and ecology ...................................................................... 15 2.1.3. Population and damage trends ........................................................... 16 Legislation.................................................................................................... 18 Diversification and agroecological practices ............................................... 19 3. Materials and methods ........................................................................................... 20 Species, scaring sites and limitations .......................................................... 21 Scaring procedures ..................................................................................... 22 Materials ...................................................................................................... 24 3.3.1. Field materials ..................................................................................... 24 3.3.2. Data treatment and software usage.................................................... 24 3.3.3. Statistical tests .................................................................................... 26 4. Results ..................................................................................................................... 29 General features of the data set .................................................................. 29 4.1.1. Distance to nearest object .................................................................. 32 4.1.2. Correlation plots .................................................................................. 34 Linear models .............................................................................................. 37 5. Discussion............................................................................................................... 40 Discussion of results .................................................................................... 40 5.1.1. Agroecological approach .................................................................... 42 Methodological discussion........................................................................... 44 5.2.1. Reproducibility .................................................................................... 44 5.2.2. Validity due to practical issues ............................................................ 45 5.2.3. Data treatment and potential improvement ........................................ 47 6. Conclusion .............................................................................................................. 49 Abbreviations CAB County Administrative Board/Länsstyrelsen EU European Union FID Flight Initiation Distance GIS Geographic Information System GPS Global Positioning System LGB Large Grazing Birds, i.e., (in Sweden) swans, geese and cranes NVV Naturvårdsverket/Swedish Environmental Protection Agency SLU Sveriges Lantbruksuniversitet/Swedish University of Agricultural Sciences T-goose /geese Target Goose/Geese. In this thesis referring to greylag goose and barnacle goose WP Waypoint 9 1. Introduction The interactions between wild geese and humans have increased in the last 50-70 years. This is true for both Europe (Fox & Madsen 2017; Fox et al. 2017) and Sweden (Montràs-Janer 2021). The way we farm affect the numbers of geese, and farming practices and productivity are reciprocally affected by the numbers and distribution of geese. There are several goose species in the world; in Sweden nine of them occur naturally and annually (Artdatabanken 2021b).This